Orig battery (Y reg); recently left lights on - battery flat; recharged, never really convincing; no time - garage. Alternator check 12 V, worse when lights screen heater etc. In new batty. Alt check 14 V with everything on. Borrow or put a new one in before you disturb anything else! Good luck...

Thank you Mick O'Brien, TheReverend and the Confirmers of the solution(do we have a new sect here) (brilliant photies). I was about to take the passenger seat out because it won't elevate (with trepidation because I have heard that in some vehicles this can set off the air-bags). It has been...